Helman, Paul. <br/><br/>
Walls and mirrors :  intermediate problem solving and data structures / 
Paul Helman and Robert Veroff. 
 - Menlo Park :  The Benjamin/ Cummings Publishing Company Inc.,  1988. 
 - xxiv, 625 p. :  ill. ;  23 cm. 
 - Modula-2 edition. .
<br/><br/> Includes Index. 
<br/><br/>Includes bibliographical references.   
<br/><br/><label>ISBN: </label>0805389458 (pbk.) 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Modula-2.<br/>Data structures (computer Science).<br/>Electronic digital computers-Programming.